What Difference does it make?
We began this unit by discussing what it means to be green and why our choices today will impact the future. We went on to talk about renewable vs. non-renewable energy sources and how non-renewable sources are limited and negatively impact our environment.
Further along in this lesson we discussed why non-renewable energy sources can greatly enhance the lifestyles of the people in certain communities. We took a "trip" to West Africa to see how many women in villages normally cook their traditional cornmeal dish. Normally this would mean that women or children would have to walk miles to find firewood, make a fire, then spend at least 30 minutes cooking over a hot fire. This was an inconvenience for many reasons: the lack of readily available wood in their communities, time spent cooking vs. getting other chores done, not to mention that this process had to be repeated for each meal of the day. However, engineers, companies, and world help groups are getting solar ovens in the hands of West African citizens in order to use solar energy to cook their normal meals!
Further along in this lesson we discussed why non-renewable energy sources can greatly enhance the lifestyles of the people in certain communities. We took a "trip" to West Africa to see how many women in villages normally cook their traditional cornmeal dish. Normally this would mean that women or children would have to walk miles to find firewood, make a fire, then spend at least 30 minutes cooking over a hot fire. This was an inconvenience for many reasons: the lack of readily available wood in their communities, time spent cooking vs. getting other chores done, not to mention that this process had to be repeated for each meal of the day. However, engineers, companies, and world help groups are getting solar ovens in the hands of West African citizens in order to use solar energy to cook their normal meals!
Solar oven boxes
Using the Engineering is Elementary site, students watched an instructional video in order to build their basic solar oven box. All boxes need to be very similar, if not identical, because they are going to be our CONTROL in our solar oven experiment.
Testing insulators
How could we make our solar oven boxes perform better than just an empty box with plastic and foil on it? We could add something that would hold the captured heat in - an insulator. In this lesson we discussed what insulators do and how we use them all of the time to keep our hot things hot and our cold things cold. We went on to test five different materials in an ice bath to see how well they kept the temperatures inside of a cup steady.
Using data to make choices
Our next step was to share and analyze the data we gathered from our insulation testing. Reminding the students that they are designing solar ovens with role as green engineers, I challenged them to balance what worked well as an insulator and using materials that are "green" and whose use will have little to no impact on the environment.
Now each group is all set to add their insulators! Using thermometers, each group will track how well their solar oven is capturing and holding heat. As an added bonus and to give the kids a visual, we also put some S'Mores ingredients in our solar oven boxes. Would they capture and hold enough heat for the ingredients to melt together for a yummy snack?
Now each group is all set to add their insulators! Using thermometers, each group will track how well their solar oven is capturing and holding heat. As an added bonus and to give the kids a visual, we also put some S'Mores ingredients in our solar oven boxes. Would they capture and hold enough heat for the ingredients to melt together for a yummy snack?
How did we do?
As solar ovens were doing their thing, groups began to score their designs. Not only was each group rewarded for capturing and retaining as much heat as possible, they were also given bonuses if their design was green. After our test and calculating scores, the groups will have one chance to improve their solar oven's "greenness" and performance.